Preliminary application of volumetric-modulated arc therapy dosimetry verification system based on three-dimensional dose reconstruction of patient anatomical structures
Ma Yangguang1, Mai Rizhen2, Pei Yuntong1, Guo Yuexin1
1Department of Radiation Oncology, First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China; 2Department of Medical Equipment, First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
Abstract：Objective To perform testing and clinical application of a volumetric-modulated arc therapy (VMAT) dosimetry verification system based on three-dimensional dose reconstruction of patient anatomical structures. Methods ArcCheck array calibration was performed. Then, 200MU was delivered with a 10cm×10cm field when the source to center of ArcCheck was 100cm to calibrate the absolute dose and the dose was simultaneously measured by a FC65-G detector in the center of the ArcCheck. The absolute dose calibration value or the CT value of ArcCheck was adjusted to minimize the differences between the planning and measurement values of FC65-G, reconstructed value by 3DVH and reconstructed percent depth dose by 3DVH. 10 lung and 10 cervical cancer VMAT cases were selected and measured by ArcCheck and FC65-G under the delivery of a TrueBeam LINAC. The three-dimensional doses of all cases were reconstructed by 3DVH and compared with the planning and measurement values. Results Different array calibration files of ArcCheck exerted different effect upon the two-dimensional dose measured by ArcCheck and three-dimensional dose reconstructed by 3DVH. The optimal reconstructed dose was obtained when self-calibration file was adopted and 249.96cGy was regarded as the absolute dose calibration value. The deviations of the mean dose (Dmean) and D95% of the target were within ±4.2% and parameters of some organs at risk significantly differed compared with the reconstructed and planning dose for all cases. A negative mean point dose difference was obtained and the reconstructed dose was closer to the measured value. The γ-passing rate of the target for some cases was low, the proportion of regions irradiated by 50% prescription dose was slightly higher and the proportion of other organs was relatively high. Conclusion The 3DVH model can be accurately established and tested with the acceptance test method in the present study, which can provide detailed information for dose verification.
Ma Yangguang,Mai Rizhen,Pei Yuntong et al. Preliminary application of volumetric-modulated arc therapy dosimetry verification system based on three-dimensional dose reconstruction of patient anatomical structures[J]. Chinese Journal of Radiation Oncology, 2022, 31(2): 170-175.
[1] Miften M, Olch A, Mihailidis D, et al. Tolerance limits and methodologies for IMRT measurement-based verification QA:recommendations of AAPM task group No.218[J]. Med Phys, 2018, 45(4):e53-e83. DOI:10.1002/mp.12810. [2] Park JM, Kim JI, Park SY, et al. Reliability of the gamma index analysis as a verification method of volumetric modulated arc therapy plans[J]. Radiat Oncol, 2018, 13(1):175. DOI:10.1186/s13014-018-1123-x. [3] Ohira S, Ueda Y, Isono M, et al. Can clinically relevant dose errors in patient anatomy be detected by gamma passing rate or modulation complexity score in volumetric-modulated arc therapy for intracranial tumors?[J]. J Radiat Res, 2017, 58(5):685-692. DOI:10.1093/jrr/rrx006. [4] Vieillevigne L, Molinier J, Brun T, et al. Gamma index comparison of three VMAT QA systems and evaluation of their sensitivity to delivery errors[J]. Phys Med, 2015, 31(7):720-725. DOI:10.1016/j.ejmp.2015.05.016. [5] Nelms BE, Chan MF, Jarry G, et al. Evaluating IMRT and VMAT dose accuracy:practical examples of failure to detect systematic errors when applying a commonly used metric and action levels[J]. Med Phys, 2013, 40(11):111722. DOI:10.1118/1.4826166. [6] Yi X, Lu WL, Dang J, et al. A comprehensive and clinical-oriented evaluation criteria based on DVH information and gamma passing rates analysis for IMRT plan 3D verification[J]. J Appl Clin Med Phys, 2020, 21(8):47-55. DOI:10.1002/acm2.12910. [7] Low C, Toye W, Phung P, et al. Patient-specific quality assurance protocol for volumetric modulated arc therapy using dose volume histogram[J]. J Med Phys, 2018, 43(2):112-118. DOI:10.4103/jmp. JMP_138_17. [8] van der Bijl E, van Oers RFM, Olaciregui-Ruiz I, et al. Comparison of gamma-and DVH-based in vivo dosimetric plan evaluation for pelvic VMAT treatments[J]. Radiother Oncol, 2017, 125(3):405-410. DOI:10.1016/j.radonc.2017.09.014. [9] Cozzolino M, Oliviero C, Califano G, et al. Clinically relevant quality assurance (QA) for prostate RapidArc plans:gamma maps and DVH-based evaluation[J]. Phys Med, 2014, 30(4):462-472. DOI:10.1016/j.ejmp.2014.01.003. [10] Carrasco P, Jornet N, Latorre A, et al. 3D DVH-based metric analysis versus per-beam planar analysis in IMRT pretreatment verification[J]. Med Phys, 2012, 39(8):5040-5049. DOI:10.1118/1.4736949. [11] Zhen H, Nelms BE, Tomé WA. Moving from gamma passing rates to patient DVH-based QA metrics in pretreatment dose QA[J]. Med Phys, 2011, 38(10):5477-5489. DOI:10.1118/1.3633904. [12] Commissioning ArcCHECK with 3DVH[Z]. Hague:Sun Nuclear Corporation, 2017. [13] 3DVH reference guide complete 3D patient dose analysis[Z]. Florida:Sun Nuclear Corporation, 2017. [14] Nelms BE, Opp D, Robinson J, et al. VMAT QA:measurement-guided 4D dose reconstruction on a patient[J]. Med Phys, 2012, 39(7):4228-4238. DOI:10.1118/1.4729709. [15] Tamborra P, Martinucci E, Massafra R, et al. The 3D isodose structure-based method for clinical dose distributions comparison in pretreatment patient-QA[J]. Med Phys, 2019, 46(2):426-436. DOI:10.1002/mp.13297. [16] Infusino E, Mameli A, Conti R, et al. Initial experience of ArcCHECK and 3DVH software for RapidArc treatment plan verification[J]. Med Dosim, 2014, 39(3):276-281. DOI:10.1016/j.meddos.2014.04.004. [17] Low C, Toye W, Phung P, et al. Patient-specific quality assurance protocol for volumetric modulated arc therapy using dose volume histogram[J]. J Med Phys, 2018, 43(2):112-118. DOI:10.4103/jmp. JMP_138_17. [18] 陈阿龙,陈立新,陈利,等. 基于三维影像解剖结构的调强剂量验证的初步研究[J]. 中华放射肿瘤学杂志,2014, 23(4):352-356. DOI:10.3760/cma.j.issn.1004-4221.2014.04.019. Chen AL, Chen LX, Chen L, et al. Preliminary study on intensity modulation dose validation based on three-dimensional imaging anatomy[J]. Chin J Radiat Oncol, 2014, 23(4):352-356. DOI:10.3760/cma.j.issn.1004-4221.2014.04.019. [19] 张俊,王昊,谢丛华,等. 基于解剖结构的三维剂量验证系统物理模型测试及应用[J]. 中国医学物理学杂志,2015, 32(4):474-478. DOI:10.3969/j.issn.1005-202X.2015.04.005. Zhang J, Wang H, Xie CH, et al. Testing and application of 3-D dose verification system based on anatomy[J]. Chin J Med Phys, 2015, 32(4):474-478. DOI:10.3969/j.issn.1005-202X.2015.04.005.
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